Benefit of Dynamic Strut Rod (and other Suspension Q’s)

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chinze57

chinze57

Push Button tranny and a Slant 6 that'll never die
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Title says the bulk of it. I’ve now been in the car with the new 225. I forgot just how floaty the car felt.

I’m planning on in the next few months going for 1.03” torsion bars, 5 or 6 leaf ESPO rear leaf springs, tubular UCAs and new brakes, and doing all new poly bushings in the suspension. Poly is tighter and I think more in-line with what I want from the car.

I’ve seen recommendations to go for dynamic strut rods, what benefit do they provide?

Will a sway bar help a lot in the front for cornering, or will the bigger torsion bars already be significantly better?

Im putting 15x6 wheels with 215/60/15 tires on the car. I did also recently switch to Bilstein shocks which are markedly better than the ones that were on it
 
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First, you have to consider what the strut rod does. Because the LCA is attached at a single point, the strut rod is there to locate and stabilize the LCA. Because of the single attachment point, under hard braking or acceleration the LCA will be pushed forward or backward by the suspension forces acting out at the ball joint. The strut rod triangulates the LCA, and by being attached close to the ball joint it keeps the LCA from moving around. GM calls them a "brake reaction rod", which describes their function a bit more.

The factory used large rubber bushings to attach the strut rod to the chassis (K frame). Those large bushings can actually absorb some shock, like if you drop your wheel into a giant pothole. The LCA is pushed back (the car is moving forward) and that big old rubber bushing can act as a shock absorber. It was also a bit of a cheat, the length of the strut rod is pretty important because the strut rod and LCA travel in different arcs. These cars weren't perfect, and the big rubber bushing made up for the strut rods being the same length for every A-body rolling off the line even though the suspension points had significant factory tolerances (like a 1/4").

The problem with that is that the big old rubber bushing also allows the LCA to move around more when those forces are applied. Moving the LCA forward or backward can dramatically change the caster angle of the suspension. The harder you push the car, the more suspension load you put on the LCA, and the more the LCA will flex that large rubber strut rod bushing so it can move around.

So, the "dynamic" or adjustable strut rod does a few things. First, and most importantly, it allows you to tune the length of the strut rod to match YOUR suspension. The more your suspension differs from the factory suspension the more important this is. I generally recommend anyone planning on running poly or Delrin LCA bushings also run adjustable strut rods. The poly and Delrin bushings are not the same as factory, they do not function exactly the same as factory, and because of that the length of the strut rod is even more critical. Since you're eliminating flex, the length of the strut rod is more important. If the strut rod is not the right length, the LCA and strut rod can bind as they move through their different arcs as the suspension travels. That binding effects how the suspension reacts, which effects handling. It can also change the alignment numbers as I mentioned before. So IMO the biggest advantage to the adjustable strut rods is that they can be tuned so that the LCA (and the rest of the suspension) moves through its entire range of travel without binding. The factory suspension rarely did that. On top of that, because the adjustable strut rods eliminate the big old rubber bushing, they control the movement of the LCA more accurately. The LCA stays put, the alignment numbers stay closer to what they're supposed to be, and the suspension motion is more precise. The less flex and slop in the suspension components themselves the more accurate the handling will be.

The drawback is that you actually have to tune the length of the strut rod. Meaning, you can't just slap it in there. You need to assemble the suspension and move it through its full range of travel to check for binding. Do that properly and you'll get a much smoother, bind free suspension travel. Do it wrong and you'll get even worst binding than the factory parts with all of their flex and slop. The process requires you to cycle the suspension through its range of travel to check for binding, then change the length of the strut rod, cycle the suspension again to check for binding, repeat until the binding is entirely gone (or effects the smallest range of travel possible). So it can take some time if you don't start close to the right length. Once you've done it a few times it goes pretty fast though.

As for the rest of it, the larger torsion bars will help but you'll still probably want a front and rear sway bar to further stabilize the car. It does depend on how the rest of the car is set up, and 215's are pretty narrow tires. The bigger the tires the more force will end up in the suspension and chassis and the stiffer things need to be. Still, when I was running my Duster with 1" torsion bars and 225/60/15's all the way around it definitely could have used a set of sway bars.
 
72bluNblu said:
First, you have to consider what the strut rod does. Because the LCA is attached at a single point, the strut rod is there to locate and stabilize the LCA. Because of the single attachment point, under hard braking or acceleration the LCA will be pushed forward or backward by the suspension forces acting out at the ball joint. The strut rod triangulates the LCA, and by being attached close to the ball joint it keeps the LCA from moving around. GM calls them a "brake reaction rod", which describes their function a bit more.

The factory used large rubber bushings to attach the strut rod to the chassis (K frame). Those large bushings can actually absorb some shock, like if you drop your wheel into a giant pothole. The LCA is pushed back (the car is moving forward) and that big old rubber bushing can act as a shock absorber. It was also a bit of a cheat, the length of the strut rod is pretty important because the strut rod and LCA travel in different arcs. These cars weren't perfect, and the big rubber bushing made up for the strut rods being the same length for every A-body rolling off the line even though the suspension points had significant factory tolerances (like a 1/4").

The problem with that is that the big old rubber bushing also allows the LCA to move around more when those forces are applied. Moving the LCA forward or backward can dramatically change the caster angle of the suspension. The harder you push the car, the more suspension load you put on the LCA, and the more the LCA will flex that large rubber strut rod bushing so it can move around.

So, the "dynamic" or adjustable strut rod does a few things. First, and most importantly, it allows you to tune the length of the strut rod to match YOUR suspension. The more your suspension differs from the factory suspension the more important this is. I generally recommend anyone planning on running poly or Delrin LCA bushings also run adjustable strut rods. The poly and Delrin bushings are not the same as factory, they do not function exactly the same as factory, and because of that the length of the strut rod is even more critical. Since you're eliminating flex, the length of the strut rod is more important. If the strut rod is not the right length, the LCA and strut rod can bind as they move through their different arcs as the suspension travels. That binding effects how the suspension reacts, which effects handling. It can also change the alignment numbers as I mentioned before. So IMO the biggest advantage to the adjustable strut rods is that they can be tuned so that the LCA (and the rest of the suspension) moves through its entire range of travel without binding. The factory suspension rarely did that. On top of that, because the adjustable strut rods eliminate the big old rubber bushing, they control the movement of the LCA more accurately. The LCA stays put, the alignment numbers stay closer to what they're supposed to be, and the suspension motion is more precise. The less flex and slop in the suspension components themselves the more accurate the handling will be.

The drawback is that you actually have to tune the length of the strut rod. Meaning, you can't just slap it in there. You need to assemble the suspension and move it through its full range of travel to check for binding. Do that properly and you'll get a much smoother, bind free suspension travel. Do it wrong and you'll get even worst binding than the factory parts with all of their flex and slop. The process requires you to cycle the suspension through its range of travel to check for binding, then change the length of the strut rod, cycle the suspension again to check for binding, repeat until the binding is entirely gone (or effects the smallest range of travel possible). So it can take some time if you don't start close to the right length. Once you've done it a few times it goes pretty fast though.

As for the rest of it, the larger torsion bars will help but you'll still probably want a front and rear sway bar to further stabilize the car. It does depend on how the rest of the car is set up, and 215's are pretty narrow tires. The bigger the tires the more force will end up in the suspension and chassis and the stiffer things need to be. Still, when I was running my Duster with 1" torsion bars and 225/60/15's all the way around it definitely could have used a set of sway bars.
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Thank you for the excellent information. It sounds like no matter what I do, properly tuned adjustable strut rods are the way to go. I’ll also plan to install sway bars as well. However, I am a bit confused as to how they mount in the rear, is that something you can provide insight on?
 
I use rubber bushings and factory upper and lower control arms with stock strut rods. MOOG makes heavy duty strut rod rubber bushings. I ran Poly bushings for decades and got tired of the noise and harshness. Went back to heavy duty rubber bushings everywhere, except the sway bar links, and love the feel. Check your lower ball joints for wear as well as your idler arm and tie rod ends, especially the outers. Look at the A Body high performance cars suspension. 6 leaf rear springs, .88 torsion bars, front sway bar, rarely do you need a rear bar on an A Body, and good shocks. If everything in the front suspension is good, that will put a smile on most drivers faces.
 
chinze57 said:
Thank you for the excellent information. It sounds like no matter what I do, properly tuned adjustable strut rods are the way to go. I’ll also plan to install sway bars as well. However, I am a bit confused as to how they mount in the rear, is that something you can provide insight on?
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Depends on the style. Some are over axel like FirmFeel and bolt to the frame rail in the arch, others are under axel mounted and bolt lower on the rail...
 
chinze57 said:
Thank you for the excellent information. It sounds like no matter what I do, properly tuned adjustable strut rods are the way to go. I’ll also plan to install sway bars as well. However, I am a bit confused as to how they mount in the rear, is that something you can provide insight on?
Click to expand...

I'll see if I can get some pictures of the rear sway bars. It does depend on if they're frame or axle mounted. Hellwig and Hotchkis are both axle mounted and need end link mounts added to the frame.

66fs said:
I use rubber bushings and factory upper and lower control arms with stock strut rods. MOOG makes heavy duty strut rod rubber bushings. I ran Poly bushings for decades and got tired of the noise and harshness. Went back to heavy duty rubber bushings everywhere, except the sway bar links, and love the feel. Check your lower ball joints for wear as well as your idler arm and tie rod ends, especially the outers. Look at the A Body high performance cars suspension. 6 leaf rear springs, .88 torsion bars, front sway bar, rarely do you need a rear bar on an A Body, and good shocks. If everything in the front suspension is good, that will put a smile on most drivers faces.
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Moog does not currently make strut rod bushings for the 73-76 strut rods. They are out of stock everywhere. I have recently had my orders of the Moog K7068 strut rod bushings cancelled by Jegs, Amazon, Summit and Rock Auto. Regardless, you don't want to just add stiffer strut rod bushings in the original style. That's why I don't recommend poly strut rod bushings. The strut rod bushing deals with motion in two primary directions, up and down as the suspension travels, and forward and backward with braking and acceleration. Having a stiffer bushing for braking and acceleration is good, it would limit the LCA moving around. But, having a stiffer bushing for the up and down travel of the suspension is BAD. It will add binding at the ends of the range of suspension travel, and that's not what you want. The adjustable strut rods solve both of those issues- they constrain the front and back movement of the LCA and move freely up and down.

There is nothing high performance about .88" torsion bars. A car with .88" torsion bars is still dramatically undersprung for handling purposes, even without wide front tires. I ran my Duster with 1" torsion bars, boring old monroe replacement shocks, and 225/60/15 tires. It was still undersprung in the front, with lots of front end dive and body roll. Now, the 1.12" torsion bars I run now would have been too stiff for the grip I was getting from the 225/60/15's, but work great with the 275/35/18's I have now. But even the 1" bars weren't enough for more performance minded handling with 225/60/15's, and those tires weren't anything extreme.

Poly bushings will not make noise if properly lubricated. If your poly bushings are making noise, you're not maintaining them properly. Period. There is no argument there, it's just the facts. Properly maintained poly bushings do not make noise. If they're squeaking they're either dry, dirty, or worn out. Usually they're worn out because they dried up. The MUST be lubricated. I have also run them for decades, and mine have never made noise when I have taken care of them as they should be.

The rear sway bar thing is also BS. Whether or not your car needs a rear sway bar has almost nothing to do with it being an A-body and everything to do with how the suspension on the rest of the car is set up. Yeah, with .88" torsion bars a rear sway bar will rarely be necessary because the front of the car is undersprung. Adding a rear sway bar will make the rear of the car stiffer than the front and put you in oversteer. But it's not because the rear is too stiff, it's because the front is too soft. My Duster absolutely needs a rear sway bar to balance the suspension front and rear.
 
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72bluNblu said:
... Moog does not currently make strut rod bushings for the 73-76 strut rods. They are out of stock everywhere. I have recently had my orders of the Moog K7068 strut rod bushings cancelled by Jegs, Amazon, Summit and Rock Auto. Regardless, you don't want to just add stiffer strut rod bushings in the original style. That's why I don't recommend poly strut rod bushings. The strut rod bushing deals with motion in two primary directions, up and down as the suspension travels, and forward and backward with braking and acceleration. Having a stiffer bushing for braking and acceleration is good, it would limit the LCA moving around. But, having a stiffer bushing for the up and down travel of the suspension is BAD. It will add binding at the ends of the range of suspension travel, and that's not what you want. The adjustable strut rods solve both of those issues- they constrain the front and back movement of the LCA and move freely up and down.

There is nothing high performance about .88" torsion bars. A car with .88" torsion bars is still dramatically undersprung for handling purposes, even without wide front tires. I ran my Duster with 1" torsion bars, boring old monroe replacement shocks, and 225/60/15 tires. It was still undersprung in the front, with lots of front end dive and body roll. Now, the 1.12" torsion bars I run now would have been too stiff for the grip I was getting from the 225/60/15's, but work great with the 275/35/18's I have now. But even the 1" bars weren't enough for more performance minded handling with 225/60/15's, and those tires weren't anything extreme.

Poly bushings will not make noise if properly lubricated. If your poly bushings are making noise, you're not maintaining them properly. Period. There is no argument there, it's just the facts. Properly maintained poly bushings do not make noise. If they're squeaking they're either dry, dirty, or worn out. Usually they're worn out because they dried up. The MUST be lubricated. I have also run them for decades, and mine have never made noise when I have taken care of them as they should be.

The rear sway bar thing is also BS. Whether or not your car needs a rear sway bar has almost nothing to do with it being an A-body and everything to do with how the suspension on the rest of the car is set up. Yeah, with .88" torsion bars a rear sway bar will rarely be necessary because the front of the car is undersprung. Adding a rear sway bar will make the rear of the car stiffer than the front and put you in oversteer. But it's not because the rear is too stiff, it's because the front is too soft. My Duster absolutely needs a rear sway bar to balance the suspension front and rear.
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I've done all that, and you can keep your BS. None of that theoretical BS is needed for most of us who just want a good handling street car. All of my stuff is maintained very well. I'm just stripping all the polyurethane out of my last A Body suspension as we speak. I don't need your road race stuff. Not everyone can tolerate the same harshness. As for a totally balanced suspension you have to do what you have to do. But does the OP with a 225/6 need your suspension? I doubt it. I'll never put a rear sway bar till I tried it without it.
 
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66fs said:
I've done all that, and you can keep your BS. None of that theoretical BS is needed for most of us who just want a good handling street car. All of my stuff is maintained very well. I'm just stripping all the polyurethane out of my last A Body suspension as we speak. I don't need your road race stuff. Not everyone can tolerate the same harshness. As for a totally balanced suspension you have to do what you have to do. But does the OP with a 225/6 need your suspension? I doubt it. I'll never put a rear sway bar till I tried it without it.
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It's not just theoretical, it's literally how the suspension on these cars works. If you've ever bothered to take the time to cycle the suspension on these cars back and forth through the entire range of travel with factory and aftermarket parts and compare the differences you can literally SEE and FEEL what I'm talking about. I run the set up just like I described it, and I run it on the street. Between my '72 Challenger and my '74 Duster I have over 100k street driven miles on poly bushings in various different locations, as well as on my adjustable strut rods. I put over 70k street driven miles on "dynamic strut bars" identical to the ones QA1 sells now. They work, and they're significant improvement over stock.

It's not "road race stuff" either. It's performance handling "stuff". Properly tuned it's not harsh either. More than likely your suspension was harsh with the poly bushings because your undersized .88" torsion bars were still allowing the suspension to bottom out, and if you replaced the factory rubber bump stops with poly ones that would be harsh. All the components have to work together, if you just slap poly bushings in with all the factory parts and do nothing else they will not perform as they're intended.

Poly bushings that are squeaking are improperly lubricated. Just the simple truth, nothing you say will change that because it's just reality. This is why I always install poly bushings with a way to lubricate them. Unlike rubber bushings poly bushings are not maintenance free, they must be lubricated. They're not any different than any other high performance part- they're not like factory parts that you can install and forget about for 100k miles. Lubricate poly bushings on a regular interval (like greaseable ball joints) with the proper poly grease and they will never squeak. What happens when your ball joints dry out? The wear rapidly and start making noise. Same exact thing with poly bushings, it's literally the same concept.

The OP's 225 /6 has very little to do with how well his car handles. You can have a great handling car with a 225. It might not have as much power as a V8 equipped car, but there's no reason it has to handle like a barge like it did from the factory just because it has a /6 in it.

And there's proof that these parts work all over the place. You can look up how the Hotchkis Challenger compared to a Challenger SRT8. You can look up how the Hotchkis taxi performed on TireRack's track compared to the 3 series BMW's they normally use. With some relatively simple upgrades you can take these cars out of the last century and get them to handle on par with plenty of new cars. And for a car that is frequently driven on the street, that will mean you can actually drive the thing without worrying about getting wrapped around a pole or left in the dust by a new 4 banger commuter car. You take the theory of suspension design, apply it to the suspension on these cars, and make practical upgrades to match the suspensions function with modern tires that grip better than what the factory ever designed this suspension for.

Hotchkis Challenger vs Challenger SRT

2010 Dodge Challenger SRT-8 vs. 1970 Dodge Challenger | Edmunds

Hotchkis Taxi (4 door satellite!!!) vs Beemers


Challenger that cleans up at autoX competitions with torsion bars...
’70 Challenger On Factory-Style Suspension is an Autocross Warrior
 
Ok what is all this "dynamic?" Is this simply "a buzz word" for an ADJUSTABLE strut?
 
67Dart273 said:
Ok what is all this "dynamic?" Is this simply "a buzz word" for an ADJUSTABLE strut?
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Its just what QA1 calls their adjustable strut rods.

The only thing I can think with QA1 calling them “dynamic” is that they use a double threaded stud at the LCA end. Which makes them easier to adjust than the other kind that just use a bolt to go through the LCA into the threaded strut rod tube. So maybe that’s what they mean, since the QA1 version is truly double adjustable on the car.

With the other kind you can adjust the length of the tube, but then you need to tighten the bolt at the LCA end still, which can change the length again. Makes finding the proper length (for no binding on the LCA) a little trickier. I’ve used both styles but prefer the QA1’s.
 
My 100% factory stock, worn out and rotted suspension was harsher than after installing QA1 rods and urethane bushings.
Then I swapped in Viking double adjustable shocks and it'd a world of difference vs the stock suspension.

I really am convinced that it doesn't matter what bushings or balljoints one runs. If the shocks are junk (and if they're regularly stocked at parts stores, they're junk) then the car will suck on the road.
 
Here’s what I’ll say, I like a good handling car. While I’ve been getting the new engine and working on that over the past several months, my daily driver has been a 2017 Fiat 124 Spider. I’m a sucker for a car that can corner.

I’m willing to sacrifice some ride quality for improved handling. At freeway speeds the car feels like it’s floating. When braking there’s a lot of nosediving.

I’m hoping that higher spring rates can start to help with some of that. I will be replacing my UCAs as my old ones are failing and I’m replacing them with some new tubular ones and new brakes.

Im willing to do maintenance on poly bushings for tighter movement and better handling. Like I said in my original post, I think that poly lines up with what I seek from my car.
 
Phreakish said:
My 100% factory stock, worn out and rotted suspension was harsher than after installing QA1 rods and urethane bushings.
Then I swapped in Viking double adjustable shocks and it'd a world of difference vs the stock suspension.

I really am convinced that it doesn't matter what bushings or balljoints one runs. If the shocks are junk (and if they're regularly stocked at parts stores, they're junk) then the car will suck on the road.
Click to expand...

I dunno that I would go as far as saying it doesn’t matter at all what bushings or ball joints you run. There are differences in performance between them.

However, I wholeheartedly agree that most of the people that blame their "harsh" ride on poly bushings are probably misplacing the blame from another component.

Suspension is a system, everything has to work together. Which is why I regularly tell people that don't want to use adjustable strut rods and greaseable LCA pivot pins not to use poly. It's not because poly isn't better (it is!), but because it's not the same as rubber and requires different parts to work with it.

chinze57 said:
Here’s what I’ll say, I like a good handling car. While I’ve been getting the new engine and working on that over the past several months, my daily driver has been a 2017 Fiat 124 Spider. I’m a sucker for a car that can corner.

I’m willing to sacrifice some ride quality for improved handling. At freeway speeds the car feels like it’s floating. When braking there’s a lot of nosediving.

I’m hoping that higher spring rates can start to help with some of that. I will be replacing my UCAs as my old ones are failing and I’m replacing them with some new tubular ones and new brakes.

Im willing to do maintenance on poly bushings for tighter movement and better handling. Like I said in my original post, I think that poly lines up with what I seek from my car.
Click to expand...

Yes sir! I think you're on the right track. Poly bushings with adjustable strut rods and greaseable pins, combined with tubular UCA's with additional caster built in and larger torsion bars will give you a car with much better, more modern handling.

As far as brakes go, if you use the 73+ spindles you can combine them with the later B/R body 11.75 rotors and 2.75" piston calipers, which will still fit in 15" wheels and will provide for much improved braking.
 
72bluNblu said:
However, I wholeheartedly agree that most of the people that blame their "harsh" ride on poly bushings are probably misplacing the blame from another component.
Click to expand...

That's more what I meant. Poly and rubber have different applications and approaches, but I don't see poly as creating a harsh ride if the damping is done correctly.

Same goes for any change to the suspension. Anything that frees up suspension movement (reduces binding) will require additional damping.
 
72bluNblu said:
It's not just theoretical, it's literally how the suspension on these cars works. If you've ever bothered to take the time to cycle the suspension on these cars back and forth through the entire range of travel with factory and aftermarket parts and compare the differences you can literally SEE and FEEL what I'm talking about. I run the set up just like I described it, and I run it on the street. Between my '72 Challenger and my '74 Duster I have over 100k street driven miles on poly bushings in various different locations, as well as on my adjustable strut rods. I put over 70k street driven miles on "dynamic strut bars" identical to the ones QA1 sells now. They work, and they're significant improvement over stock.

It's not "road race stuff" either. It's performance handling "stuff". Properly tuned it's not harsh either. More than likely your suspension was harsh with the poly bushings because your undersized .88" torsion bars were still allowing the suspension to bottom out, and if you replaced the factory rubber bump stops with poly ones that would be harsh. All the components have to work together, if you just slap poly bushings in with all the factory parts and do nothing else they will not perform as they're intended.

Poly bushings that are squeaking are improperly lubricated. Just the simple truth, nothing you say will change that because it's just reality. This is why I always install poly bushings with a way to lubricate them. Unlike rubber bushings poly bushings are not maintenance free, they must be lubricated. They're not any different than any other high performance part- they're not like factory parts that you can install and forget about for 100k miles. Lubricate poly bushings on a regular interval (like greaseable ball joints) with the proper poly grease and they will never squeak. What happens when your ball joints dry out? The wear rapidly and start making noise. Same exact thing with poly bushings, it's literally the same concept.

The OP's 225 /6 has very little to do with how well his car handles. You can have a great handling car with a 225. It might not have as much power as a V8 equipped car, but there's no reason it has to handle like a barge like it did from the factory just because it has a /6 in it.

And there's proof that these parts work all over the place. You can look up how the Hotchkis Challenger compared to a Challenger SRT8. You can look up how the Hotchkis taxi performed on TireRack's track compared to the 3 series BMW's they normally use. With some relatively simple upgrades you can take these cars out of the last century and get them to handle on par with plenty of new cars. And for a car that is frequently driven on the street, that will mean you can actually drive the thing without worrying about getting wrapped around a pole or left in the dust by a new 4 banger commuter car. You take the theory of suspension design, apply it to the suspension on these cars, and make practical upgrades to match the suspensions function with modern tires that grip better than what the factory ever designed this suspension for.

Hotchkis Challenger vs Challenger SRT

2010 Dodge Challenger SRT-8 vs. 1970 Dodge Challenger | Edmunds

Hotchkis Taxi (4 door satellite!!!) vs Beemers


Challenger that cleans up at autoX competitions with torsion bars...
’70 Challenger On Factory-Style Suspension is an Autocross Warrior
Click to expand...


You still miss my point. I am not talking autocross or road racing. Been there done all that. I'm talking about a street car you can drive all day long, be rock solid on the road and easily take any corner one would encounter on a real road. If the OP starts with a factory HP suspension, rubber bushings and all. Replaces all loose components, and torques everything to spec, and gets a good alignment he would probably be happy. Especially compared to the nothing suspension they put on /6 cars. When I did the 66 I wanted to go back to original, but was pleasantly surprised with the result. No need to worry about last century, I've put 250,00 street miles on a 96 Neon ACR. I've driven Porshe, Vettes, 2009 Challenger R/T, the 66 Formula S does fine with the original leaf springs, control arms, front sway bar, Bilstein shocks, 16:1 factory manual box, and whimpy .88 torsion bars. All that being said, The rebuilt suspension on the 67 Barracuda will replace polygraphite bushings with rubber. The only trick pieces will be Firm Feel upper control arms with rubber bushings, a roller bearing idler arm, and a 20:1 manual box. Everything is a compromise somewhere. I've done my time with polygraphite and high dollar for little gain stuff. What you want is not necessarily what I want.
 
66fs said:
You still miss my point. I am not talking autocross or road racing. Been there done all that. I'm talking about a street car you can drive all day long, be rock solid on the road and easily take any corner one would encounter on a real road. If the OP starts with a factory HP suspension, rubber bushings and all. Replaces all loose components, and torques everything to spec, and gets a good alignment he would probably be happy. Especially compared to the nothing suspension they put on /6 cars. When I did the 66 I wanted to go back to original, but was pleasantly surprised with the result. No need to worry about last century, I've put 250,00 street miles on a 96 Neon ACR. I've driven Porshe, Vettes, 2009 Challenger R/T, the 66 Formula S does fine with the original leaf springs, control arms, front sway bar, Bilstein shocks, 16:1 factory manual box, and whimpy .88 torsion bars. All that being said, The rebuilt suspension on the 67 Barracuda will replace polygraphite bushings with rubber. The only trick pieces will be Firm Feel upper control arms with rubber bushings, a roller bearing idler arm, and a 20:1 manual box. Everything is a compromise somewhere. I've done my time with polygraphite and high dollar for little gain stuff. What you want is not necessarily what I want.
Click to expand...

You may be right, but in my experience the "stock replacement" parts available today are not as good as the OEM stuff, and in most cases is garbage.

Hell, the factory style of strut rod bushing that came out of my car is not available today - I'd have to use junk china-moog parts to replace them and even if they fit (they won't) they won't last.

In the past 5 years, the decline in quality of parts for older cars has cratered. It was bad before but good parts was a matter of brand - not anymore IMO. Even moog has totally dropped the ball. Kinda makes trying to piece together an OEM style suspension a non-starter, at least to me.

So far, the poly parts have all been transparent as far as ride feel - but I give credit to the new shocks because they're better able to damp the freer moving suspension that poly gives me.
 
Phreakish said:
You may be right, but in my experience the "stock replacement" parts available today are not as good as the OEM stuff, and in most cases is garbage.

Hell, the factory style of strut rod bushing that came out of my car is not available today - I'd have to use junk china-moog parts to replace them and even if they fit (they won't) they won't last.

In the past 5 years, the decline in quality of parts for older cars has cratered. It was bad before but good parts was a matter of brand - not anymore IMO. Even moog has totally dropped the ball. Kinda makes trying to piece together an OEM style suspension a non-starter, at least to me.

So far, the poly parts have all been transparent as far as ride feel - but I give credit to the new shocks because they're better able to damp the freer moving suspension that poly gives me.
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Unfortunately, I feel the same about new parts. I'm sure decent stuff is available through PST and Firm Feel though. Luckily, I have all the good stuff I need in my stash. I felt the Poygraphite bushings were fine, except the lower control arm bushing. I prefer the good rubber bushing now. Everybody is different what they want and that also changes with time and usage.
 
66fs said:
Unfortunately, I feel the same about new parts. I'm sure decent stuff is available through PST and Firm Feel though. Luckily, I have all the good stuff I need in my stash. I felt the Poygraphite bushings were fine, except the lower control arm bushing. I prefer the good rubber bushing now. Everybody is different what they want and that also changes with time and usage.
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Agreed. You're lucky to have a good stash! I got into the a-body game late, and have to deal with what I can get today, which is not much (when it comes to OEM style and quality parts).

I'm a fan of "if it works, it works". I think most things can be made to work, but sometimes the juice ain't worth the squeeze. $700 shocks to make $40 bushings feel OEM-like isn't a great route for everyone. My future plans are far more big-tire and handling oriented, and so it made sense for me.
 
Which adj strut rod would people prefer Hotchkiss, QA1, FirmFeel, or PST? I am in the market for one and leaning toward Hotchkiss.... since its made from steel vs AL
 
Joeycurl said:
Which adj strut rod would people prefer Hotchkiss, QA1, FirmFeel, or PST? I am in the market for one and leaning toward Hotchkiss.... since its made from steel vs AL
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I initially bought the QA1 strut rods. At the same time I replaced my LCA's, UCA's, and even the K-member. The QA1 LCA's on my 70 Duster (as well as the OE LCA's) have the strut rod opening at 5/8". The LCA end of the QA1 strut rod is only 9/16". Because the QA1 strut rod is smaller than the LCA opening even after tightening the rod could move around causing noise and eventually wallow out the hole. I returned the QA1 rods to Summit and bought the rods from PST. Those rods are correct.
 
@72bluNblu , Question for you. I notice my torsion bar mount front & rear, and strut rod bushing (rubber pivot point) all line up. I have RMS strut rods ready to go on the car when I start assembly. The pivot point on the RMS rods is further back and outboard of the hole in the K frame. Not by much, but if we are talking about smooth, bind free travel, a different arc is a different arc.
The hole in the K frame/rubber bushing IS the pivot point in the factory design. The RMS piece is a bolt through some solid bushings at the K frame, then a bracket that holds a heim joint, then the joint itself.
I haven't gotten as far as assembly yet to feel it as it swings up & down, so I could be concerned about nothing, but I've been cycling this through my mind for way too long.
 
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Been a while since I’ve been on the site. I ended up going with the BAC lower control arm boxing kit, the torsion bars they had, the strut rods (which I believe are QA1, forgive me if I’m wrong I’m not looking at the part right this second).
I got tubular UCAs from PST, which required picking up a new brake kit from doctordiff. I made a mistake when ordering which was entirely my fault, I jumped the gun when I should have waited for a reply and done more research, so thank you to the person at doctordiff who was patient and helped me out.
I also have installed Bilstein shocks front and rear. What I can say about all of this is, it’s tightened a lot of stuff up. I can corner no issue, even with 24:1 power steering. There’s no sway bar in the front or rear but there’s not really much body roll in the front with the thick torsion bars. I highly recommend the change.
I need to get new leaf springs for the rear, I’m thinking 5 or 6 leaf, but can’t decide. Right now if I hit a bump, for a few seconds theres a bounce coming from the back, I think it’s because there’s such a difference in the stiffness front to rear.
 
Joeycurl said:
Which adj strut rod would people prefer Hotchkiss, QA1, FirmFeel, or PST? I am in the market for one and leaning toward Hotchkiss.... since its made from steel vs AL
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I prefer the QA1. You don't need steel strut rods for strength, it just adds weight. The purpose of the strut rods is just to keep the LCA from moving too far forward or back under braking/acceleration, they do not support the weight of the car. I have over 70k street miles on the aluminum CAP (bought out by QA1) strut rods on my Challenger. They also use a double adjuster, so tuning the length is much easier than with the other styles that use a bolt through the LCA end.

RogerRamRod said:
@72bluNblu , Question for you. I notice my torsion bar mount front & rear, and strut rod bushing (rubber pivot point) all line up. I have RMS strut rods ready to go on the car when I start assembly. The pivot point on the RMS rods is further back and outboard of the hole in the K frame. Not by much, but if we are talking about smooth, bind free travel, a different arc is a different arc.
The hole in the K frame/rubber bushing IS the pivot point in the factory design. The RMS piece is a bolt through some solid bushings at the K frame, then a bracket that holds a heim joint, then the joint itself.
I haven't gotten as far as assembly yet to feel it as it swings up & down, so I could be concerned about nothing, but I've been cycling this through my mind for way too long.
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Yes, adjustable strut rods have a slightly shorter effective length than the factory strut rods. They're all slightly different, but basically the way the heim is mounted on every design out there moves the pivot point back from the factory location.

But the holes being "lined up" is irrelevant. The factory strut rod and the LCA are not the same length, and their arcs are still at an angle to each other. So even if they were the same length (they are not), the paths still diverge. And get this, the pivot point on the factory strut rods can move. The rubber bushings stretch and compress under braking and acceleration loads, and that means the pivot point is not always centered between the washers.

Here's the deal, and I don't care what other members have said here. I have never had an issue tuning the length of the adjustable strut rods on my cars so that there was no binding within the range of the suspension travel. Don't get me wrong, the end of the strut rod and the end of the LCA trace out different arcs, which means if they travel far enough they will absolutely bind. But within the range of travel of the suspension on my cars I've always been able to adjust the length of the strut rod so there was no binding between the bump stops.

chinze57 said:
Been a while since I’ve been on the site. I ended up going with the BAC lower control arm boxing kit, the torsion bars they had, the strut rods (which I believe are QA1, forgive me if I’m wrong I’m not looking at the part right this second).
I got tubular UCAs from PST, which required picking up a new brake kit from doctordiff. I made a mistake when ordering which was entirely my fault, I jumped the gun when I should have waited for a reply and done more research, so thank you to the person at doctordiff who was patient and helped me out.
I also have installed Bilstein shocks front and rear. What I can say about all of this is, it’s tightened a lot of stuff up. I can corner no issue, even with 24:1 power steering. There’s no sway bar in the front or rear but there’s not really much body roll in the front with the thick torsion bars. I highly recommend the change.
I need to get new leaf springs for the rear, I’m thinking 5 or 6 leaf, but can’t decide. Right now if I hit a bump, for a few seconds theres a bounce coming from the back, I think it’s because there’s such a difference in the stiffness front to rear.
Click to expand...

The spring rate and the arch is much more important than whether the spring is a 5 or 6 leaf. Most of the performance handling springs are close to zero arch, with a spring rate around 130 lb/in. That's what you're looking for.
 
72bluNblu said:
I dunno that I would go as far as saying it doesn’t matter at all what bushings or ball joints you run. There are differences in performance between them.

However, I wholeheartedly agree that most of the people that blame their "harsh" ride on poly bushings are probably misplacing the blame from another component.

Suspension is a system, everything has to work together. Which is why I regularly tell people that don't want to use adjustable strut rods and greaseable LCA pivot pins not to use poly. It's not because poly isn't better (it is!), but because it's not the same as rubber and requires different parts to work with it.



Yes sir! I think you're on the right track. Poly bushings with adjustable strut rods and greaseable pins, combined with tubular UCA's with additional caster built in and larger torsion bars will give you a car with much better, more modern handling.

As far as brakes go, if you use the 73+ spindles you can combine them with the later B/R body 11.75 rotors and 2.75" piston calipers, which will still fit in 15" wheels and will provide for much improved braking.
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Where would you say the delrin LCA bushings fit in? I mean as far as having greasable pins VS no? I'm looking at and probably going to get the Bergman pins and delrin bushings from Peter after talking with him a while back. I've seen that delrin is essentially "self lubricating". Is it that good that it doesn't require a greasable pin? I know the ones Peter sells are not greasable. Thanks.
 
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